updated 5/04/11

Contrast Hydrotherapy

How to use hot and cold water to speed healing from injuries

by Paul Ingraham, Vancouver, Canada

Contrasting uses alternation between heating and cooling to assist with rehabilitation from several common injuries, especially plantar fasciitis, ankle sprains, shin splints, carpal tunnel syndrome, and tennis elbow.

Contrasting, or contrast hydrotherapy, involves first heating and then cooling a body part, or even the whole body. The major purpose of contrasting is to force your nervous and circulatory systems to adapt to the sudden changes in temperature, which is stimulatory, feels great, and probably has numerous minor benefits.1 It is a cheap and safe way to attempt to both soothe and stimulate irritated or healing tissue without overstimulating it. Experimenting with contrasting should be standard part of rehab from most musculoskeletal injuries.

Not strong medicine

Contrasting probably has minor benefits, but it’s unlikely to work any miracles. There is no reason to believe that contrasting would make a large difference in healing.

A few good scientific studies could tell us how effective contrasting actually is, but unfortunately the subject has barely ever been studied, and the small amount of research that has been done is of such poor quality that it’s basically useless.2

How and where to use contrast hydrotherapy

There are many ways to heat up and cool your body parts, and I encourage you to use your imagination and all the tools at your disposal. Here are a few examples.

Arms are the easiest: a double sink works very well. Fill one with hot water and one with cold and move back and forth. If you only have one sink, it’s often possible to simply switch from a flow of hot water to a flow of cold, especially if it’s a deep sink.
Lower legs are more difficult. A pair of deep buckets is a bit of work, but very effective. A removable shower nozzle is perfect.
The thighs or hips are nearly impossible, but I’ve pulled it off using a combination of hot bath with a large bin of cold water used as a sitz bath. Feels great!
On the body, you can use combinations of heating pads or hot towels with ice gel packs or ice cups (see Icing for Injuries, Tendinitis and Inflammation). These can also be used to good effect elsewhere.

Whatever you come up with, there are just a few rules of thumb to follow:

Avoid contrasting the freshest injuries that are still hot, swollen, and/or red, because the heat may aggravate the inflammation more than the cooling phase can control. You should use just ice on a fresh injury (note an important exception: back pain is usually not an “injury” per se, and should not be iced). Wait about three days for an injury like an ankle sprain to calm down a bit before you start contrasting it.
You should apply heat very thoroughly, at least a minute or as long as five minutes depending on how efficient your heating method is.
If you stretch, stretch after the heating, obviously. If you can, stretch while you are heating. If you have to stop heating to stretch, reheat after stretching before moving on to the cold.
Always finish every contrast session with cold. Never finish with heat!
It is desirable (though not always practical) to increase the intensity of the contrast as you go: that is, the hot gets hotter and the cold gets colder. For instance, when I contrast my arms, I start with two sinks of regular hot and cold tap water — but for the second cycle, I dump a little boiling water into the hot, and add a tray of ice cubs to the cold! Thus the 2nd round of contrasting is much more intense.

Is the shower good enough?

To some extent you can contrast in the shower. Whole body contrasting is nice and probably healthful in some general ways, but has limited value for rehabilitating from injuries, which require more intense temperatures, more accurately applied. Immersion of the body part is always the best. Intense heating of only the arm by dipping it in hot water, for instance, tends to cause much greater capillary dilation in the arm than the hottest shower.

The hottest and coldest showers are generally just too hot and too cold to tolerate on large areas of your body … or even just from the splashing if your trying to spray just one part of your body.

A detachable shower head, however, allows you to focus the spray enough to achieve a reasonably good effect.

How much contrasting is enough contrasting?

Precision with dosage of contrasting is not particularly important. Heat and cool in roughly one-minute doses. But if you stick to the idea of “make it good and hot, and then make it good and cold” you’re doing it right.

And how many times should you cycle between hot and cold? Just a single time — one dose of hot, one dose of cold — is a minimal help. Three times is much more of a help, and is probably a good number. Six times is just tedious! There are practical considerations.

And how many times per day? Roughly once per day. More would undoubtedly be better — perhaps three times per day, for a few days, for a situation where contrasting is particularly easy and ideal for the injury — but there are usually strict practical limits on how much contrasting people can do, or should do.

It’s helpful, but it’s not so good that you should be spending half your day doing it!

This may be powerful medicine in some situations: don’t underestimate its usefulness just because it sounds a bit odd! Try it, have fun, enjoy the sensations, and you may find it more effective at helping you heal than medications or therapy.

The thermal workout

Another interesting application of contrasting is the “thermal workout.” Full body contrasting — switching back and forth between hot tub and pool, for instance — can be surprisingly exhausting and physiologically potent.

It can even be dangerous, so for pity’s sake be careful and use some common sense:

Steer clear of this if you have virtually any kind of general health problem, especially cardiovascular disease, or even just low blood pressure.
The older you are, the more careful you should be.
Don’t be extreme with the temperatures, and do not underestimate how potent full-body contrasting can be even at more modest temperatures.
And stay hydrated! This is an important to prevent a surprise drop in blood pressure.
If you get light-headed, get out, get down, and discontinue the exercise.

Seriously, do not even think about trying this without going slow and taking it easy. This is one of those ideas that desperately needs a medical disclaimer! If you get into trouble doing this, it’s not because I didn’t warn you! Those warnings you see around public hot tubs and saunas? They are not for nothing!

Okay, I hope that’s enough ranting about the dangers to fully cover my butt.

Done safely, even a gentle thermal workout is ideal for wearing yourself out and burning some calories without straining anatomy, and that’s can be a handy component of a rehabilitation or general fitness regimen.

For instance, I often cluster workouts as close together as I dare. If I play competitive sports on Tuesday night, I may be pretty sore the next day and just barely have time for my body to recover for my next strength training workout on Friday. And yet I don’t want to be a lazy butt for three solid days. A thermal workout is a perfect way to poop myself out a bit without loading my tissues up with more stress than they can adapt to.

Updates

Thursday, March 18, 2010 — Added reference to Hing.

Notes

Boyle, Wade, and Saine, André. Lectures in Naturopathic Hydrotherapy. Sandy, Oregon: Eclectic Medical Publications. 1988. BACK TO TEXT
Hing et al. Contrast therapy—a systematic review. Physical Therapy in Sport. 2008. PubMed #19083715. Abstract:
Contrast therapy is a strategy that is widely utilised in a number of sporting codes to aid recovery. This wide use might suggest that contrast therapy is an effective recovery modality however support for this assumption appears to be mainly anecdotal. The purpose of this paper is to review the efficacy of contrast therapy. To achieve this objective, a systematic review of randomised controlled trials (RCTs) that have specifically evaluated the therapeutic efficacy of contrast therapy was performed. A search to identify appropriate literature was conducted across a number of electronic databases. The titles and abstracts of the papers identified were reviewed to select papers specifically relating to contrast therapy. Twelve RCTs met the inclusion and exclusion criteria. The PEDro Scale, a systematic tool used to critique RCTs, was employed to critique the methodological quality of these studies. This review highlights both the lack in quantity and quality of research regarding the efficacy of contrast therapy for sports recovery. There appears to be insufficient evidence that contrast therapy aids in recovery and the limited methodological quality of the reviewed studies makes it difficult to draw clear conclusions about this form of therapy. Future research needs to re-examine the use of contrast therapy and in particular whole body immersion recovery strategies within the appropriate sports setting. This research will need to be of sufficient quality to enable appropriate conclusions to be made with regards to its use as a recovery strategy.
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